Conventionally mounting systems have been known, and a mounting system includes a battery unit capable of storing a secondary battery, an electronic device, to which such a battery unit can be attached detachably, and a mounting device to mount the battery unit and/or the electronic device. Examples of the electronic device include a printer, a video camera, and a personal computer. The mounting device may be called a cradle.
Patent Literature 1, for example, describes a mobile printer including a secondary battery built therein and a cradle to mount the mobile printer, and the secondary battery can be charged when the mobile printer is mounted on the cradle.
Such a mounting device to mount an electronic device and the like often has a terminal that is exposed to be in contact with a terminal of the electronic device to be mounted. A known mounting device therefore is configured to prevent the short circuit between the terminals due to water entry. Patent Literature 2, for example, describes a charger having a positive terminal and a negative terminal covered with a side wall. The battery charger is configured to limit contact of these terminals with water by providing a partition wall to divide a space surrounded with the side wall.
Conventionally a printer having a body to which a battery can be attached has been known. Patent Literature 3, for example, describes such a printer. This printer includes a printer body and a locking device to lock the body with a battery case for connection. The printer body has a container, for example, defined at the bottom face to store the battery case. Patent Literature 4 describes a small printer having a battery container.